CHAPTER VIII. 



NON-STRIPED MUSCULAR TISSUE. 



78. THIS tissue consists of nucleated cells, which, 

 unlike amoeboid cells, are contractile in one definite 

 direction, becoming shorter and thicker during con- 

 traction. 



The cells are elongated, spindle-shaped, or band-like 

 (Fig. 38A), and drawn out at each extremity into a longer 

 or shorter, generally single but occasionally branched, 

 tapering process. Each cell includes an oval nucleus, 



Fig. 38A. Nou-striped Muscular Fibres, isolated. 



The cross-markings indicate corrugations of the elastic sheath of the individual 

 fibres. (Atlas.) 



which is flattened if the cell it belongs to is flattened. 

 The cell-substance is a pale homogeneous-looking or 

 longitudinally striated substance. 



During extreme contraction the nucleus may be- 

 come more or less plicated, so that its outline becomes 

 wavy or zig-zag. 



It has been shown by Klein in certain preparations, 

 e.g., the non-striped muscle cells of the mesentery of 

 the newt, that each muscle cell consists of a delicate 



